1. Field of the Invention
The present invention relates to a method for making a three-dimensional device.
2. Description of Related Art
In conventional processes for making three-dimensional devices such as three-dimensional ICs, a first layer including field effect transistors (FETs) is formed on an Si substrate by a multiple of steps. Next, a similar second layer is formed on the first layer. A third layer and the subsequent layers are then similarly formed thereon.
In the conventional processes for making three-dimensional devices, however, these layers are deposited on the same substrate; hence, overlying layers must be formed so as not to adversely affect the layer thereunder with various restrictions, for example, the upper temperature limit, so that the underlying layers are not affected.
When different layers are deposited, it is very difficult to produce these layers at desired device parameters, for example, gate-line width, thickness of the gate insulating film, design rule, and process conditions such as production temperature.
In addition, in the conventional methods for making three-dimensional devices, these layers are formed on a substrate constituting a device. Thus, the substrate used must have adaptability as a substrate for a device and adaptability as a substrate for forming these layers. Since usable substrates are limited, the methods are disadvantageous.
Accordingly, three-dimensional devices such as three-dimensional ICs have not been actually used.
It is an object of the present invention to provide a method for making three-dimensional devices under a wide variety of forming conditions for thin film device layers, and for facilitating production of high-performance three-dimensional devices.
Such an object is achieved by the following embodiments (1) to (22) according to the present invention.
(1) A method for making a three-dimensional device which may consist of depositing in the thickness direction a plurality of thin film device layers disposed in a predetermined region in the two-dimensional direction, wherein at least one of the thin film device layers is deposited by a transfer process.
(2) A method for making a three-dimensional device constituting a three-dimensional circuit which may consist of depositing in the thickness direction a plurality of thin film device layers constituting a circuit disposed in a predetermined region in the two-dimensional direction on a substrate, wherein at least one of the thin film device layers is deposited by a transfer process.
(3) The method for making a three-dimensional device according to (1) or (2) above, wherein the transfer process may consist of forming a thin film device layer on a first substrate with a cleaving layer provided therebetween, and irradiating the cleaving layer with illuminating light so as to form cleavage in the cleaving layer and/or at the interface thereof and to transfer the thin film device layer on the first substrate onto a second substrate side.
(4) The method for making a three-dimensional device according to (3) above, wherein the cleavage of the cleaving layer is generated by breakage or attenuation of atomic or molecular bonding force of substances constituting the cleaving layer.
(5) The method for making a three-dimensional device according to (3) above, wherein the cleavage of the cleaving layer is generated by gas evolved from the substance constituting the cleaving layer.
(6) The method for making a three-dimensional device according to any one of (3) to (5) above, wherein the illuminating light is laser light.
(7) The method for making a three-dimensional device according to (6) above, wherein the wavelength of the laser light is 100 to 350 nm.
(8) The method for making a three-dimensional device according to (6) above, wherein the wavelength of the laser light is 350 to 1,200 nm.
(9) The method for making a three-dimensional device according to any one of (3) to (8) above, wherein the cleaving layer may consist of amorphous silicon, ceramic, metal or an organic polymer.
(10) The method for making a three-dimensional device according to any one of (3) to (9) above, wherein the first substrate is a transparent substrate.
(11) The method for making a three-dimensional device according to any one of (1) to (10) above, wherein each of the thin film device layers is provided with connecting electrodes, and the connecting electrodes electrically connect the two adjacent thin film device layers.
(12) The method for making a three-dimensional device according to (11) above, wherein the connecting electrodes are disposed on the two surfaces of the thin film device layer.
(13) The method for making a three-dimensional device according to (11) or (12) above, wherein the two adjacent thin film device layers are bonded to each other with an anisotropic conductive film therebetween.
(14) The method for making a three-dimensional device according to any one of (1) to (10) above, wherein in the two selected layers among the thin film device layers, one of the two selected layers is provided with a light emitting section and the other layer is provided with a light receiving section for receiving the light from the light emitting section, the light emitting section and the light receiving section enabling optical communication between the two layers.
(15) The method for making a three-dimensional device according to any one of (1) to (14) above, wherein the thin film device layer deposited by the transfer is simultaneously produced with at least one of the other thin film device layers.
(16) The method for making a three-dimensional device according to any one of (1) to (15) above, wherein at least one of the thin film device layers has a plurality of thin film transistors.
(17) The method for making a three-dimensional device according to any one of (1) to (16) above, wherein the thin film device layers as memory are transferred a plurality of times to form a large-scale memory.
(18) The method for making a three-dimensional device according to any one of (1) to (16) above, wherein the thin film device layers as logic are transferred a plurality of times to form a large-scale logic.
(19) The method for making a three-dimensional device according to any one of (1) to (16) above, wherein the thin film device layers as memory and the thin film device layers as logic are transferred to form a system LSI.
(20) The method for making a three-dimensional device according to (19) above, wherein the logic and the memory are formed by different design rules.
(21) The method for making a three-dimensional device according to (19) above, wherein the logic and the memory are formed by different design parameters.
(22) The method for making a three-dimensional device according to (19) above, wherein the logic and the memory are formed by different production processes.
FIG. 1 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 2 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 3 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 4 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 5 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 6 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 7 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 8 is a schematic cross-sectional view of a step in an embodiment of a transfer process of a thin film structure in accordance with the present invention.
FIG. 9 is a schematic cross-sectional view of a configuration of a three-dimensional device in accordance with the present invention.
FIG. 10 is a schematic cross-sectional view of a step in a first embodiment of a method for making a three-dimensional device in accordance with the present invention.
FIG. 11 is a schematic cross-sectional view of a step in a first embodiment of a method for making a three-dimensional device in accordance with the present invention.
FIG. 12 is a schematic cross-sectional view of a step in a first embodiment of a method for making a three-dimensional device in accordance with the present invention.
FIG. 13 is a schematic cross-sectional view of a step in a first embodiment of a method for making a three-dimensional device in accordance with the present invention.
FIG. 14 is a schematic cross-sectional view of a step in a first embodiment of a method for making a three-dimensional device in accordance with the present invention.
FIG. 15 is a schematic cross-sectional view of a step in a first embodiment of a method for making a three-dimensional device in accordance with the present invention.
FIG. 16 is a schematic cross-sectional view of another configuration of a three-dimensional device in accordance with the present invention.
FIG. 17 is a schematic cross-sectional view of another configuration of a three-dimensional device in accordance with the present invention.
FIG. 18 is a schematic cross-sectional view of another configuration of a three-dimensional device in accordance with the present invention.
FIG. 19 is a cross-sectional view of a configuration of an organic electroluminescent (EL) device in accordance with the present invention.
FIG. 20 is a cross-sectional view of a configuration of a PIN photodiode in accordance with the present invention.